"This is not an isolated incident," British Airline Pilots Association's (Balpa's) general secretary Jim McAuslan said. "Aircraft are attacked with lasers at an alarming rate and with lasers with ever-increasing strength."

Media captionA recording of a crew member speaking to air traffic controllers has emerged

"Modern lasers have the power to blind and certainly to act as a huge distraction and to dazzle the pilots during critical phases of flight."

Former pilot and fellow member of the pilot's union Dave Smith said legislation on lasers - first introduced in 2010 - should be much tougher.

"The law from 2010 is just an offence of shining the laser into the cockpit, but of course that is very difficult to prove," he said.

Balpa is calling for sales of all but the lowest power devices to be regulated.

"Lasers should be specifically included in the offensive weapons legislation so that if someone is found to be carrying a laser without good reason then they are treated in the same way as if they are carrying a knife," a spokeswoman added.

'Over the internet'

But Dr John O'Hagan, a laser safety expert at Public Health England, believes the existing laws are adequate.

"Our recommendation is that only low-powered lasers, one milliwatt - one thousandth of a watt - should be generally available to the public.

"And in the UK now it is relatively unusual to be able to buy a laser, that looks like a laser pointer, that's at a higher power. The trouble is that you can buy them over the internet at much higher powers."

Lasers produce a concentrated, pencil-like beam of light which can be directed over large distances.

They vary in strength and have a wide variety of uses, including CD readers, printers, barcode scanners, presentational aids, DIY alignment tools and medical surgery.

It is the misuse of laser pointers, sometimes referred to as laser pens, which is generating concern.

'Precautionary measure'

Last year, a man who targeted a Police Scotland helicopter with a laser pen was jailed for 12 months after detectives used thermal imaging equipment to locate him.

Craig Ryan, 23, shone the beam at the aircraft from his garden in Stevenston, forcing the pilot to take evasive action.